Distech Controls BACnet MS/TP Manual
Distech Controls’ quality management system is ISO 9001:2000 certified
1. Product Description
The BACnet MS/TP repeater is a designed to extend your network
beyond the 4,000 feet range limitation of RS-485.
The repeater also augments the RS-485 signal to allow more
devices on a single channel.
Figure 1-1: BACnet MS/TP Repeater
2. General Installation Requirements
For proper installation and subsequent operation of the repeater,
pay special attention to the following recommendations:
- Upon unpacking the product, inspect the contents of the carton
for shipping damages. Do not install a damaged unit.
- Allow for proper clearance of device enclosure and wiring
terminals for easy access, hardware configuration and
maintenance.
- The device is designed to operate under the following
environmental conditions:
Ambient temperature from -13°F to 167°F (-25°C to 75°C)
Relative humidity from 10% to 90%, non-condensing.
- Ensure proper ventilation of device and avoid areas where
corroding, deteriorating or explosive vapors, fumes or gases
may be present.
Any type of modification to any Distech Controls product
will void the product’s warranty.
Take reasonable precautions to prevent electrostatic
discharges to the device when installing, servicing or
operating it. Discharge accumulated static electricity by
touching one’s hand to a securely grounded object before
working with the device.
3. General Wiring Recommendations
Turn off power before any kind of servicing.
Do not use more than two (2) repeaters on a BACnet
MS/TP data bus.
- All wiring must comply with electrical wiring diagrams as well
as national and local electrical codes.
- To connect the wiring to the device, use the terminal
connectors which are located at the extremities of the device’s
enclosure. Use a small flat screwdriver to tighten the terminal
connector screws once the wires have been inserted.
- It is recommended that the communication cable used follows
the BACnet Network Guide.
4. Mounting Instructions
Each controller can be mounted on a DIN rail to speed up the
installation process. Multiple devices can be stacked together via
the included din rail provided in the packaging.
5. Device Dimensions
Hardware Installation Guide
Distech Controls, Inc.
Toll-free: 1-800-404-0043
Tel. International: 450-444-9898
www.distech-controls.com
BACnet®MS/TP Repeater
Unit Legend: mm
Distech Controls, Inc.
Toll-free: 1-800-404-0043
Tel. International: 450-444-9898
www.distech-controls.com
Figure 5-1: Device Dimensions
6. Device Wiring
The repeater has physical connections for up to five (3) different
connections. These connections include the following:
Power (+10 VDC to +30 VDC non-isolated)
Data input
Data output 1
Wiring
Figure 6-1: Device connections
A repeater can be added anywhere to a data bus as shown below.
Figure 6-2: Using a repeater to extend the range of the LAN
Do not use more than two (2) repeaters on a BACnet MS/TP data
bus.
A repeater is counted as a device on each data bus on which it is
connected.
Make sure the shield is connected to the electrical system ground at
one point on the channel. The shield coming into the repeater and
out of the repeater should be twisted together and isolated with
electrical tape.
When third party devices are connected to the data bus, the number
of devices that can be connected may be reduced. Refer to section
“Maximum Number of BACnet MS/TP Devices on a Data Bus
Segment” in the BACnet Network Guide for more information.
7. LED Indicator
The LED embedded in the repeater represents the following
information:
Red: When power is connected the LED will be a solid red
color.
Orange: When data is being transmitted (sending and receiving)
the LED will flash orange.
Data Bus Shields: Twist
together and Isolate
with electrical tape
Typical BACnet DeviceRepeaterTypical BACnet Device
Data Bus: Shielded Twisted Pair Cable
NET+
NET-
NET+
NET-
The shield of the data bus must be connected to the electrical system
ground at one point only –usually at the Building Controller, when present
Data + (1)
Data –(2)
Data + (20)
Data –(19)
120 Ω120 Ω
Distech Controls, Inc.
Toll-free: 1-800-404-0043
Tel. International: 450-444-9898
www.distech-controls.com
BACnet MSTP Repeater_IG_10_EN
8. Troubleshooting Guide
Hardware Installation Guide - BACnet MS/TP Repeater
05DI-HIREPT-10
©Copyright Distech Controls Inc. First printed June 2010
While all efforts have been made to verify the accuracy of information in this manual, Distech Controls is not responsible for damages or claims arising from the use of
this manual. Persons using this manual are assumed to be trained HVAC specialist / installers and are responsible for using the correct wiring procedures and
maintaining safe working conditions with fail-safe environments. Distech Controls reserves the right to change, delete or add to the information in this manual at any
time without notice.
Distech Controls and the Distech Controls logo are trademarks of Distech Controls Inc.
BACnet® is a registered trademark of American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE);
All other trademarks are property of their respective owners.
Device communicates well over a short network, but does not communicate on large network
Network length
Check that the total wire length does not exceed the specifications listed in the BACnet Network Guide
Wire type
Check that the wire type agrees with the specification of the listed in the BACnet Network Guide
Network wiring problem
Double check that the wire connections are correct.
Absent or incorrect network termination
Check the termination(s). Incorrect or broken termination(s) will make the communication integrity dependent upon a
device’s position on the network.
Number of devices on network segment
exceeded
It is recommended that the number of devices on a channel should not exceed 50. Use a router or a repeater in
accordance to the BACnet Network Guide.
